Buggy code:
public static final int Empty = ASTNode . Bit19 ; public static final int IsElseIfStatement = ASTNode . Bit30 ; public static final int ThenExit = ASTNode . Bit31 ; public static final int IsElseStatementUnreachable = ASTNode . Bit8 ; public static final int IsThenStatementUnreachable = ASTNode . Bit9 ; public static final int IsSuperType = ASTNode . Bit5 ; public static final int IsVarArgs = ASTNode . Bit15 ; public static final int IgnoreRawTypeCheck = ASTNode . Bit31 ; public static final int IsAnnotationDefaultValue = ASTNode . Bit1 ; public static final int IsNonNull = ASTNode . Bit18 ; public static final int NeededScope = ASTNode . Bit30 ; public static final int OnDemand = ASTNode . Bit18 ; public static final int Used = ASTNode . Bit2 ; public static final int DidResolve = ASTNode . Bit19 ; public static final int IsAnySubRoutineEscaping = ASTNode . Bit30 ; public static final int IsSynchronized = ASTNode . Bit31 ; public static final int BlockExit = ASTNode . Bit30 ; public static final int IsRecovered = ASTNode . Bit6 ; public static final int HasSyntaxErrors = ASTNode . Bit20 ; public static final int INVOCATION_ARGUMENT_OK = 0 ; public static final int INVOCATION_ARGUMENT_UNCHECKED = 1 ; public static final int INVOCATION_ARGUMENT_WILDCARD = 2 ; public ASTNode ( ) { } private static int checkInvocationArgument ( BlockScope scope , Expression argument , TypeBinding parameterType , TypeBinding argumentType , TypeBinding originalParameterType ) { } public static boolean checkInvocationArguments ( BlockScope scope , Expression receiver , TypeBinding receiverType , MethodBinding method , Expression [ ] arguments , TypeBinding [ ] argumentTypes , boolean argsContainCast , InvocationSite invocationSite ) { TypeBinding [ ] params = method . parameters ; int paramLength = params . length ; boolean isRawMemberInvocation = ( ( ( ! ( method . isStatic ( ) ) ) && ( ! ( receiverType . isUnboundWildcard ( ) ) ) ) && ( method . declaringClass . isRawType ( ) ) ) && ( method . hasSubstitutedParameters ( ) ) ; boolean uncheckedBoundCheck = ( ( method . tagBits ) & ( TagBits . HasUncheckedTypeArgumentForBoundCheck ) ) != 0 ; MethodBinding rawOriginalGenericMethod = null ; if ( ! isRawMemberInvocation ) { if ( method instanceof ParameterizedGenericMethodBinding ) { ParameterizedGenericMethodBinding paramMethod = ( ( ParameterizedGenericMethodBinding ) ( method ) ) ; if ( ( paramMethod . isRaw ) && ( method . hasSubstitutedParameters ( ) ) ) { rawOriginalGenericMethod = method . original ( ) ; } } } int invocationStatus = ASTNode . INVOCATION_ARGUMENT_OK ; if ( arguments == null ) { if ( method . isVarargs ( ) ) { TypeBinding parameterType = ( ( ArrayBinding ) ( params [ ( paramLength - 1 ) ] ) ) . elementsType ( ) ; if ( ! ( parameterType . isReifiable ( ) ) ) { scope . problemReporter ( ) . unsafeGenericArrayForVarargs ( parameterType , ( ( ASTNode ) ( invocationSite ) ) ) ; } } } else { if ( method . isVarargs ( ) ) { int lastIndex = paramLength - 1 ; for ( int i = 0 ; i < lastIndex ; i ++ ) { TypeBinding originalRawParam = ( rawOriginalGenericMethod == null ) ? null : rawOriginalGenericMethod . parameters [ i ] ; invocationStatus |= ASTNode . checkInvocationArgument ( scope , arguments [ i ] , params [ i ] , argumentTypes [ i ] , originalRawParam ) ; } int argLength = arguments . length ; <START_BUG> if ( lastIndex < argLength ) { <END_BUG> TypeBinding parameterType = params [ lastIndex ] ; TypeBinding originalRawParam = null ; if ( ( paramLength != argLength ) || ( ( parameterType . dimensions ( ) ) != ( argumentTypes [ lastIndex ] . dimensions ( ) ) ) ) { parameterType = ( ( ArrayBinding ) ( parameterType ) ) . elementsType ( ) ; if ( ! ( parameterType . isReifiable ( ) ) ) { scope . problemReporter ( ) . unsafeGenericArrayForVarargs ( parameterType , ( ( ASTNode ) ( invocationSite ) ) ) ; } originalRawParam = ( rawOriginalGenericMethod == null ) ? null : ( ( ArrayBinding ) ( rawOriginalGenericMethod . parameters [ lastIndex ] ) ) . elementsType ( ) ; } for ( int i = lastIndex ; i < argLength ; i ++ ) { invocationStatus |= ASTNode . checkInvocationArgument ( scope , arguments [ i ] , parameterType , argumentTypes [ i ] , originalRawParam ) ; } } if ( paramLength == argLength ) { int varargsIndex = paramLength - 1 ; ArrayBinding varargsType = ( ( ArrayBinding ) ( params [ varargsIndex ] ) ) ; TypeBinding lastArgType = argumentTypes [ varargsIndex ] ; int dimensions ; if ( lastArgType == ( TypeBinding . NULL ) ) { if ( ! ( ( varargsType . leafComponentType ( ) . isBaseType ( ) ) && ( ( varargsType . dimensions ( ) ) == 1 ) ) ) scope . problemReporter ( ) . varargsArgumentNeedCast ( method , lastArgType , invocationSite ) ; } else if ( ( varargsType . dimensions ) <= ( dimensions = lastArgType . dimensions ( ) ) ) { if ( lastArgType . leafComponentType ( ) . isBaseType ( ) ) { dimensions -- ; } if ( ( varargsType . dimensions ) < dimensions ) { scope . problemReporter ( ) . varargsArgumentNeedCast ( method , lastArgType , invocationSite ) ; } else if ( ( ( ( ( ( varargsType . dimensions ) == dimensions ) && ( lastArgType != varargsType ) ) && ( ( lastArgType . leafComponentType ( ) . erasure ( ) ) != ( varargsType . leafComponentType . erasure ( ) ) ) ) && ( lastArgType . isCompatibleWith ( varargsType . elementsType ( ) ) ) ) && ( lastArgType . isCompatibleWith ( varargsType ) ) ) { scope . problemReporter ( ) . varargsArgumentNeedCast ( method , lastArgType , invocationSite ) ; }

Fix:
if ( lastIndex <= argLength ) {